Voltage source converters (VSCs)

equipped with

$P-f$

and

$Q-U$

droop characteristics

can support a power system from both frequency and voltage. Unfortunately

overcurrent and power angle instability are still challenging aspects of VSCs under fault conditions. Therefore

fault current limitation and power angle stability are essential conditions for the safe operation of a VSC. Thus

the transient characteristics of a VSC are analyzed to guide transient control. Then

a transient control method for a VSC

considering both fault current limitation and power angle stability

is proposed. With the proposed method

power angle stability is realized by optimizing the

$P-f$

controller. On the basis of power angle control

the

$Q-U$

controller and inner current controller are improved to effectively suppress the fault current. Finally

relevant tests are performed to verify the proposed method.